Arrangement for forming a seal

ABSTRACT

The invention relates to an assembly for forming a seal between components ( 11, 33 ), which have sealing zones ( 37,51 ), said sealing zones facing each other in a functional position of the components. A sealing element ( 43, 57 ) is provided on the sealing zone ( 37, 51 ) of one component ( 11, 33 ) and a sealing surface ( 51 ) is provided on the sealing zone ( 37, 51 ) of the other component ( 11, 33 ) in order to form a radial seal, and the components ( 11, 33 ) can be brought into the functional position by a relative movement which is carried out in the axial direction, said sealing element ( 43, 57 ) sealingly interacting with the sealing surface ( 51 ) in said functional position. The invention is characterized in that the assembly has a third component ( 61 ) which is associated with an actuating part ( 62 ) that acts on the sealing element ( 43;57 ) in the functional position of the components ( 11, 33 ) so as to deform said element in order increase the sealing force.

The present invention relates to an assembly for forming a seal between components, which include sealing zones that face one another when the components are in a functional position, wherein a sealing element is provided on the sealing zone of the one component and a sealing surface is provided on the sealing zone of the other component in order to form a radial seal, and the components may be brought into the functional position by a relative movement which is carried out in the axial direction, in which functional position the sealing element interacts in a sealing manner with the sealing surface in a sealing manner.

To ensure a secure and pressure-resistant seal in radial sealing systems, a sufficiently high pressure force between sealing element and sealing surface is essential. Achieving the necessary surface pressure requires considerable deformation of the sealing element, which, in the case of sealing materials used particularly often, can range from 8% to 20%. The increase in sealing force achieved in this way results in the formation of a correspondingly strong frictional locking at the sealing points between the components sealed against each other. The corresponding assembly and disassembly operations are hampered considerably, when sealing points are involved, which must be loosened more frequently, as is the case, for example, with sealing points on replacement parts, such as spare parts or the like, or if it involves maintenance points at which the seal must be loosened more frequently. In the case of correspondingly high sealing forces, it is nearly impossible to carry out assembly operations without the help of tools or devices.

In view of this problem, the stated object of the invention is to provide an assembly which makes it possible to simply and conveniently loosen the sealing points formed, in spite of high, active sealing forces.

According to the invention, this object is achieved by an assembly, which includes the features of Claim 1 in its entirety.

According to the characterizing portion of Claim 1, the assembly according to the invention is distinguished by the inclusion of a third component which is associated with an actuating part, which acts on the sealing element in the functional position of the components so as to deform said element in order increase the sealing force. According to the invention, the deformation which increases the sealing force, because it occurs as a result of the action of the actuating part when the components are in the functional position, allows the non-deformed sealing element to be dimensioned in such a way that the relative movements of the components carried out for assembly and disassembly are easily and effortlessly accomplished since, in the case of a non-deformed sealing element, there are no high frictional forces to overcome. On the other hand, a corresponding deformation may be achieved by the action of the actuating part, which produces the compression required to secure the seal.

In a preferred embodiment of the assembly according to the invention, the axial relative movement takes place in a longitudinal direction between the third component and the two other components, wherein two sealing parts of the sealing element execute, at least partially, a radial transverse movement or closing movement transverse to the aforementioned longitudinal direction, thereby forming the radial seal, the sealing effect of which is increased all the more as, with increasing axial relative movement, the third component enters between the two sealing parts. The aforementioned longitudinal direction then conforms to the central longitudinal axis of the entire assembly.

The aforementioned sealing element, when designed preferably in the form of an elastomeric, and thus flexible, sealing ring, has a V-shape, as viewed preferably in cross-section, and the two aforementioned sealing parts then form arms of the V-shaped sealing ring to be spread apart. Instead of a V-shape, it is also feasible to select a U-shaped ring, which then has sealing parts in the form of arm portions which extend preferably outward in a visibly conical manner.

In preferred exemplary embodiments, the sealing zone of the one component is provided on an element holder of a filter housing and the sealing zone of the other component is provided on a filter element which may be inserted in and removed from the filter housing. In an application of this type, which results in large sealing diameters between element holder and filter element, the ease of the assembly operations achieved according to the invention has a particularly advantageous effect, particularly since the required filter element replacement makes it necessary to frequently separate the relevant sealing points.

The assembly may be devised in a particularly advantageous manner such that the sealing surface on the relevant component is extended in the axial direction in such a way that multiple relative axial positions of the components are permissible as functional positions forming the seal. The reliability of the seal, because it is not dependent on retaining the components in precise axial positions, eliminates the need to provide a correspondingly narrow tolerance for the installation positions of the components. This has a particularly advantageous effect, inter alia, in the case of seals between a filter element and a filter housing, because a particularly simple and cost-efficient design may be implemented, given the fact that it is unnecessary to maintain particularly narrow tolerances for either the dimensions of the filter element or the housing components that position the filter element on the element holder.

In such an application, it is preferable to provide the sealing surface on the element holder of the filter housing and the sealing element on the end cap of the relatable filter housing.

In this case, the assembly may be particularly advantageously designed so that the third component includes a movable hold-down, which, in order to hold the filter element in the corresponding installation position corresponding to the functional position of the seal, may be moved into an active position adjacent to the end cap, in which the actuating part acts on the sealing element.

In particularly preferred exemplary embodiments, the sealing element may have at least partially a V-shaped cross-section with one arm abutting the outer periphery of the end cap of the filter element and one arm interacting with the sealing surface of the element retainer, wherein an actuating part in the form of a ring projecting on the hold-down is provided, which compresses the sealing element at the hold-down adjacent to the end cap by spreading the arms between end cap and sealing surface. A design of this type is advantageous in several respects. On the one hand, the result is a simply designed system consisting of filter housing and filter element, since the hold-down functions both as a holding element of the filter element, and as an actuating element for the sealing assembly, in that the actuating part of the hold-down, by entering between the arms of the sealing element, causes the spreading deformation of the sealing element and with that the increase in the sealing force. On the other hand, the actuation, i.e., the activation of the sealing assembly occurs, for all practical purposes, automatically in the course of the fixing of the filter element on the element holder, as a result of the movement of the hold-down toward the end cap.

Further possible embodiments of the invention are specified in additional dependent claims.

The invention is explained in detail below with reference to exemplary embodiments depicted in the drawings, in which:

FIG. 1 shows a longitudinal section of a filter device, depicted in a perspective, angular view and with breaks, in which an exemplary embodiment of the assembly for forming a seal according to the invention is provided;

FIG. 2 shows a partial representation, greatly enlarged and drawn in a perspective angular view, in which only a partial section of the element holder of the filter housing of FIG. 1 and of an interacting part of a filter element with a sealing element situated on the end cap thereof according to the exemplary embodiment of the assembly according to the invention are depicted;

FIG. 3 shows an enlarged drawn partial longitudinal section, which depicts a second exemplary embodiment of the assembly according to the invention, and only the parts of an associated filter device interacting with the sealing assembly;

FIG. 4 shows a partial longitudinal section of the end cap of the filter element otherwise not shown provided with the sealing element according to the second exemplary embodiment and of a hold-down interacting with the end cap, and

FIG. 5 shows an enlarged representation of the area indicated by V in FIG. 4.

The invention is explained below with reference to exemplary embodiments, in which the assembly according to the invention is provided in a filter device for forming a seal between an element holder of a filter housing and an end cap of a filter element, which may be inserted in and removed from the filter housing. FIG. 1 shows a partially schematic, simplified representation of a corresponding filter device having a hollow cylindrically-shaped filter housing 1, which is closed at the bottom and which may be sealed at the top thereof with a removable housing cover 3. The filter element 5 which may be housed in the filter housing 1 includes a filter medium 7 as is usual in such elements, which surrounds an interior filter chamber 9 in the form of a hollow cylinder, and the ends of which are enclosed by an upper end cap 11 and a lower end cap 13. The filter element 5 is provided for a perfusion from the interior filter chamber 9 outwardly during the filtration process, thus, the filter medium 7 is surrounded by an outer support tube 15, which extends from end cap 11 to end cap 13. In the assembled functional position of the filter element 5 depicted in FIG. 1, the bottom end cap 13 is separated from the housing bottom 17 by means of multiple, preferably three, foot elements 19. Only one of the foot elements 19 is visible in the rotational position shown in FIG. 1.

The filter housing 1 includes an intake 21 for supplying the fluid to be filtered, which enters above the upper end cap 11 of the filter element 5. The upper end cap 11 includes a central opening 23 which leads into the interior filter chamber 9, such that the raw or dirty side of intake 21 continues as far as the interior filter chamber 9. Forming the bottom closure of the filter chamber 9, and with that, the raw side or dirty side during the filtering process, is a bypass valve 25, which, in the event of a corresponding differential pressure, enables the fluid to pass from the filter chamber 9 through the end cap 13 down to the housing bottom 17. Since bypass valves of this type are prior art, the bypass valve 25 in FIG. 1 is indicated merely schematically. A sieve 29 is situated upstream of the bypass valve 25 so that, in response to the bypass valve 25, no dirt passes unimpeded to the housing bottom 7 and, therefore, to the clean side 27 surrounding the filter element 5. An outlet 31 is provided on the housing 1 for discharging fluid from the clean side 27.

To fix the filter element 5 in the functional position, the filter housing 1 includes an element holder 33 in the form of an annular body, which interacts with the circumferential region of the upper end cap 11 of the filter element 5 to form the sealing assembly according to the invention, by means of which the raw side or dirty side is sealed off from the clean side 27 located on the outside of the filter element 5. Further details of a first exemplary embodiment of this assembly according to the invention are shown in FIG. 2. As is apparent from FIG. 2, the end cap 11, on the upper side of which a pivotable retaining bracket 35 is attached, includes a step 37 on its outer circumference, which forms an interior cylindrical surface 39 bordered by a radial projection 41, and thereby forming a sealing zone 37. As a result, a seat is formed for a sealing element in the form of a V-shaped molded seal. In the present example, this molded seal is formed from an elastomer material, for example, a synthetic rubber. The interior arm 45 of the molded seal 43 abuts the cylindrical surface 39, and is secured to the surface by the inherent tensioning of the molded seal 43 and/or by adhesion. The other V-arm 47, which is connected to the inner arm 45 by a profile web 49, is provided for interacting with a sealing surface 51 of the element holder 33. The circular cylindrical surface 51 includes an insertion chamfer 53 at its insertion end situated above in FIG. 2. The outer V-arm 47 of the molded seal 43 provided for sealing at the sealing surface 51 includes a radially projecting sealing bead 55. The aforementioned sealing bead 55 may also be omitted in certain applications, without impairing the sealing effect.

FIGS. 3 through 5 show a second exemplary embodiment of the assembly according to the invention, which differs from the first example solely by a modified shape of the sealing element. The region situated above the web 49 and forming the arms 45 and 47 of the modified molded seal 57, corresponds to the molded seal 43 of FIG. 2, wherein, however, a projection 59 is joined to the underside of the web 49 connecting the arms 45, 47, which, together with the web 49, forms a U-profile. The projection 59 thus formed engages with the radial projection 41 of the end cap 11 which forms the edge of the cylindrical surface 39. This forms a positive locking of the molded seal 57 against axial displacement, so that the latter is securely fixed in the event of axial loads, which occur during assembly operations.

FIGS. 1 and 3 show the installation scenario of the completed sealing assembly according to the first and the second exemplary embodiment. Provided for the actual actuation of the assembly in both exemplary embodiments is a third component, which includes an actuating part which, in the functional position, acts to deform the molded seal 43 and 57 in such a way that they are compressed between cylindrical surface 39 of the end cap 11 and the sealing surface 51 on the element holder 33 as a result of a wedge-like engagement in the intermediate space of the V-arms 45, 47. Whereas during installation operations, the outer arm 47 reaches the sealing surface 51 via the insertion chamfer 53 merely under the influence of its inherent tension, the arm 47, after the spreading deformation of the molded seal 43, 57, abuts the sealing surface 51 with the high sealing force required for an absolutely secure seal.

In both exemplary embodiments shown herein, the third component, which includes the actuating part that deforms the molded seal 43, 57 is, as can be seen in FIGS. 1 and 3, formed by an annular body 61, which may be located at the upper side of the element cap 11, and which functions as a hold-down in order to axially secure the filter element 5 to the element holder 33 in the installation position corresponding to the functional position of the sealing assembly. An axially projecting, conically tapering ring 62 is provided as the actual actuating part on the circumferential area of the annular body 61, which in the functional position, see in particular FIG. 3, acts as an expansion element between the arms 44, 47, in order to increase the sealing force, with which the arm 47 with its sealing bead 55 abuts the sealing surface 51. As is also most clearly seen in FIG. 3, the axial length of the sealing surface 51 is dimensioned so that multiple, relative axial positions of the molded seal 43, 57 are permissible for a secure seal. This eliminates the need to provide components, which maintain narrow tolerance limits, in order to position the annular body 61 provided as a hold-down for the filter element 5.

Such components associated with the annular body 61 in the examples shown are each provided in the form of axially oriented supports 63, which are screwed on their undersides to the annular body 61 and at the upper end to a magnetic holder 65. The annular body 61 is supported on the housing cover 3 by the supports 63, see FIG. 1. Attached in the central area of the magnetic holder 65 is a connecting part 67 for a so-called magnetic core 69, which extends via the opening 23 of the end cap 11 into the filter chamber 9 of the filter element 5. Such magnetic cores 69, provided with a permanent magnetic device, are prior art.

In the examples described herein, in which the opening of the V-profile faces the molded seals 43, 57 during the filtration operation of the raw side and, therefore, the side with the higher pressure acting on the sealing point, a pressure activation of the sealing assembly results during operation, in addition to the increase in sealing force caused by the deformation of the sealing element (molded seal 43, 57). 

1. An assembly for forming a seal between components (11, 33), which include sealing zones (37, 51) that face one another in a functional position of the components, wherein a sealing element (43, 57) is provided on the sealing zone (37, 51) of the one component (11, 33) and a sealing surface (51-) is provided on the sealing zone (37, 51)of the other component (11, 33) in order to form a radial seal, and the components (11, 33) may be brought into a functional position by means of a relative movement carried out in the axial direction, in which functional position the sealing element (43, 57) interacts in a sealing manner with the sealing surface (51), characterized in that the assembly has a third component (61) associated with an actuating part (62), which acts on the sealing element (43, 57) in the functional position of the components (11, 33), so as to deform the element in order increase the sealing force.
 2. The assembly according to claim 1, characterized in that as a result of the axial, relative movement in the longitudinal direction between the third component and the two other components (11, 33), two sealing parts (45, 47) of the sealing element (43, 57) execute at least partially a closing movement transverse to the longitudinal direction, thereby forming the radial seal, the sealing effect of which increases, in accordance with the extent to which the third component (61), with increasing axial relative movement, is inserted between the two sealing parts (45, 47).
 3. The assembly according to claim 1, characterized in that the sealing zone of the one component is provided on an element holder (33) of a filter housing (1) and the sealing zone of the other component (11) is provided on a filter element (5) which may be inserted in and removed from the filter housing (1).
 4. The assembly according to claim 1, characterized in that the sealing surface (51) on the relevant component (33) is extended in the axial direction in such a way that multiple, relative axial positions of the components (11, 33) are permissible as functional positions forming the seal.
 5. The assembly according to claim 1, characterized in that the sealing surface (51) is provided on the element holder (33) of the filter housing (1) and the sealing element (43, 57) is provided on the end cap (11) of the relatable filter element (5).
 6. The assembly according to claim 1, characterized in that the third component includes a movable hold-down (61), which, in order to hold the filter element (5) in the corresponding installation position corresponding to the functional position of the seal, may be moved into an active position adjacent to the end cap (11) of the relevant filter element (5), in which the actuating part (62) acts on the sealing element (43, 57).
 7. The assembly according to claim 1, characterized in that at least a part of the sealing element (43, 57) has a V-shaped cross-section, with one arm (45) abutting the outer periphery (37, 39) of the end cap (11) of the filter element (5), and one arm (47) interacting with the sealing surface (51) of the element holder (33), and that an actuating part in the form of a ring (62) projecting on the hold-down (61) is provided, which compresses the sealing element (43, 57) on the hold-down (61) adjacent to the end cap (11) by spreading the arms (45, 47) between end cap (11) and sealing surface (51).
 8. The assembly according to claim 1, characterized in that the sealing surface (51) of the element holder (33) is formed by a cylindrical surface, on one end of which an insertion chamfer (53) is formed, which radially expands the cylindrical surface.
 9. The assembly according to claim 1, characterized in that a cylindrical surface (39) is provided on the outer circumference of the end cap (11) for the attachment of the associated arm (45) of the sealing element (43, 57), which merges at one end into a radially projecting edge (41), against which a web (49) of the sealing element (43, 57) connecting the arms (45, 47) abuts.
 10. The assembly according to claim 1, characterized in that the sealing element (57) includes a projection (59) connected to the web (49) forming a U-shaped cross-section, which encloses the projecting edge (41) of the end cap (11). 